The present invention relates to a device making it possible to reclose electrical breakers automatically after they have been tripped as a result of a transient fault.
It is concerned more particularly with a device which can either be mounted independently of the breaker or be integrated in the breaker itself at the design stage of the appliance.
Hitherto, when a domestic or industrial breaker is tripped as a result of a transient fault, the protected circuit is dead until someone recloses it. Consequently, if the trip occurs during a lengthy absence, the installation is deprived of current for this entire period, and this can cause considerable damage, for example losses of frozen foodstuffs, losses of volatile computer data, deactivation of security systems, such as alarms, freeze warnings, etc.
It has therefore been proposed for a very long time to combine with the breakers means making it possible for them to be reclosed automatically. Of the devices provided for carrying out such automatic reclosing, those in most widespread use comprise an electric motor or an electromagnetic coil which is fed by an independent current source and which, by means of a suitable cinematic chain, makes it possible to actuate the setting member of the breaker in order to reclose it. Such devices are relatively heavy and bulky.
Furthermore, when the protected installation has a permanent fault, it is clear that these reclosing devices must not continue to make attempts at reclosing too often or for too long. Consequently, existing devices therefore have delay and actuation-counting systems which complicate the assembly as a whole and increase the cost.
Moreover, breakers are not standardized elements, and they can have highly variable shapes and sizes and also possess different types of actuating systems, such as pushbuttons and rocker levers. The reclosing devices therefore require special adaptation and specific adjustments according to the particular type of breaker.
Besides, it is difficult for the solutions provided hitherto, because of their complexity and cost, to be made suitable for being integrated in the breaker itself at its design stage, whereas it would be advantageous to obtain a self-reclosing appliance.
Now a device for the automatic reclosing of breakers has been found, this being the subject of the present invention, and it overcomes the disadvantages of the prior solutions and is not only of great simplicity in terms of its operating principle, but also of reduced size, and this device can either be combined with existing breakers or integrated in the breaker itself at its design stage.
In the rest of the description, the expression "independent device" will be used to denote the reclosing device according to the invention when it is simply combined with a breaker, whilst the expression "integrated device" will be used to denote a device according to the invention which forms an integral part of the breaker itself.